This invention relates in general to body and frame assemblies for vehicles. More specifically, this invention relates to an improved structure for a joint between a side rail and a cross member in such a vehicular body and frame assembly.
Many land vehicles in common use, such as automobiles, vans, and trucks, include a body and frame assembly that is supported upon a plurality of ground-engaging wheels by a resilient suspension system. The structures of known body and frame assemblies can be divided into two general categories, namely, separate and unitized. In a typical separate body and frame assembly, the structural components of the body portion and the frame portion of the vehicle are separate and independent from one another. When assembled, the frame portion of the assembly is resiliently supported upon the vehicle wheels by the suspension system and serves as a platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized use modern vehicles, such as large vans, sport utility vehicles, and trucks. In a typical unitized body and frame assembly, the structural components of the body portion and the frame portion are combined into an integral unit which is resiliently supported upon the vehicle wheels by the suspension system. Unitized body and frame assemblies of this general type are found in many relatively small modern vehicles, such as automobiles and minivans.
One well known example of a separate type of vehicular body and frame assembly is commonly referred to as a ladder frame assembly. A ladder frame assembly includes a pair of longitudinally extending side rails that are joined together by a plurality of transversely extending cross members. The cross members connect the two side rails together and provide desirable lateral, vertical, and torsional stiffness to the ladder frame assembly. The cross members can also be used to provide support for various components of the vehicle. In ladder frame assemblies intended for relatively heavy duty use, it is known that some or all of the cross members may be provided in pairs, wherein an upper cross member extends between the upper portions of the side rails and a lower cross member extends between the lower portions of the side rails.
In a typical process for forming the ladder frame assembly, the ends of the cross members (either individually or in pairs, as mentioned above) are usually initially positioned on a mounting fixture. Next, the side rails are positioned on the mounting fixture adjacent to the ends of the cross members. The side rails and the ends of the cross members are then secured together, such as by welding. However, this process has been found to be relatively difficult and time consuming to perform. This is because there is usually no structure provided on either the side rail or the cross member that provides for direct positive positioning of the side rails relative to the ends of the cross members. Although portions of the side rails and the ends of the cross members do abut one another, they can undesirably be moved or oriented in one or more directions relative to one another. Precise relative positioning of the side rails and cross members is a very important factor in the manufacture of a satisfactory ladder frame assembly. As a result, an undue amount of time is often spent to insure that the side rails and the cross members are properly aligned relative to one another prior to effecting the welding operation. Thus, it would be desirably to provide an improved structure for a joint between a side rail and a cross member in a vehicle body and frame assembly that provides for direct positive positioning of the side rails relative to the ends of the cross members to expedite the manufacturing process.